Combination fuse-mount support for projection lamps

ABSTRACT

A fused, four pin base, projection lamp having a combined stabilizing support wire and fuse for providing both alignment maintenance and electrical safety to an elaborate, multi-filament and reflector mount structure carried between a pair of laterally disposed upright rigid lead-in conductors.

14 1 Mar. 12, 1974 United States Patent 1191 De Caro et al. v

[ COMBINATION FUSE-MOUNT SUPPORT 2,179,455 11 1939 Spaeth.........

FOR PROJECTION LAMPS [75'] Inventors: Aristide R. De Caro, Edison;

Nicholas J. Rainone, Clifton, both of Prim? Kominski NJ.

Attorney, Agent, or Firm-B. R. Studebaker ABSTRACT [22] Filed:

App]. No.: 7,696

A fused, four pin base, projection lamp having a combined stabilizing support wire and fuse for providing both alignment maintenance and electrical safety to an elaborate, rnulti-filament and reflector mount 56 6 BU m 0 4H H 5 58 1 Field of 15 1 structure carried between a pair of laterally disposed upright rigid lead-in conductors.

References Cited UNITED STATES PATENTS 2,859,381 Gray et a]. 315/74 7 Claims, 2 Drawing Figures 'PMENIEU IIAR I 2 i974 INVENTORS Aristide R.. DeCaro &

Nicholas J. Rainone COMBINATION FUSE-MOUNT SUPPORT FOR PROJECTION LAMPS BACKGROUND OF THE INVENTION This invention relates generally to projection lamps and more particularly to a fused projection lamp having a longitudinal support element to maintain alignment and stability of the filament mount.

Lamp manufacturing is. a highly competitive, efficient and substantially automated industry. To remain competitive manufacturers must find methods and mechanisms by which materials can be reduced and/or manufacturing steps eliminated in order to attain increased productivity and/or reduced costs without any reduction in product quality. The elimination of a sin gle lead wire from a lamp type can result in thousands of dollars in savings over a period of a single years production. Also, the elimination of required welding steps from the manufacturing process may result in the additional savings of many dollars in the production of a particular type lamp over a'one year production run.

A projection lamp characteristically.features a plurality of compact filaments accurately positioned with respect to the lamp base and many times with respect to an internally mounted reflector for the purpose of controlling light in a projection system. The filament arrangement of a projection lamp may be biplanar or monoplanar and the filaments are generally situated in a planar array. Because of the requirement that the filament be accurately positioned and retained in that position within the lamp during manufacturing and handling, it is necessary that a longitudinal support member be employed in addition to the lateral supports upon which the filament and reflector normally are hung. 7

It is also common practice to mount a fuse wire between one of the lead-in conductor pins and the lead-in conductor support for the filament mount within the base of the lamp. A fuse is required in the projection type lamp because of the intense heat generated at a break in the filament due to the are which starts at the break and progressively shorts out greater portions of the filament. This short may grow in intensity and eventually cause the lamp bulb to shatter unless a fuse or other current limiting device is incorporated in the lamps circuit.

In the four pin projection lamp it is conventional to mount the major upstanding rigid lead-in conductors and mount supports to two laterally disposed pins at the base of the lamp with one of those pins being in electrical circuit with the socket while the other is connected only to a locator or dummy pin. A fuse, horizontally disposed within the envelope beneath the upper level of the base, generally connects the third pin which is in electrical connection to the socket circuit and the dummy pin to which the other upstanding rigid support member is connected to place the entire filament mount in electrical circuit with the socket. It is also common practice to connect a longitudinal support member between the fourth or other dead pin and one of the upstanding rigid support members in order to provide longitudinal stability to the entire filament mount. The combination of the two lateral supports and the third angular longitudinal support will then maintain the filament mount structure aligned within the lamp envelope.

SUMMARY OF THE INVENTION In summary this invention improves upon the prior art devices by providing, in a fused projection lamp having a base portion, a bulb portion sealed thereto, a plurality of support pins extending through said base portion and an elaborate filament array and support bridge therefor mounted within the bulb portion be tween a pair of upright lead-in conductor support members mounted on a pair of laterally disposed support pins, the improvement comprising: acombination fuse wire and support member connected between a third support pin and one of said upright lead-in conductor support members whereby electrical safety and longitudinal support are provided by a single element.

BRIEF DESCRIPTION OF THE DRAWING Many of the attendant advantages of the present invention will become more readily apparent and better understood as the following detailed description of an exemplary embodiment is considered in connection with the accompanying drawing in which:

FIG. 1 is a rear elevation view of a projection lamp constructed in accordance with the present invention with a portion of the outer envelope-broken away;

FIG. 2 is a sectional view taken along the line 11-11 of FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now in detail to the drawing wherein like reference characters represent like parts throughout the several views there is illustrated in FIG. 1 a projection lamp generally designated 10 which consists externally of a base portion 12 and an elongated bulb portion or outer envelope 14 hermetically sealed together by a suitable sealing composition 16. The base 12 carries a central projection 18 having an orienting key 20 for the purpose of orienting the projection lamp to the projecton system in which it is intended to be used. In addition to the central projection 18 there are also four radially disposed locating pins or terminals 22, 23, 24 and 25 which extend through glass seals 26 in the base of the bulb portion 14.

Mounted on the inner ends of a pair of laterally disposed support or locating pins as for example pins 22 and 24 is the multi-filament array of the incandescent projection lamp. This filament mounting arrangement is substantially identical to that'disclosed in U.S. Pat. No. 2,721,291 issued Oct. 18, 1955 to N. J. Rainone for an Incadescent Electric Lamp. The details of this mount arrangement are described in detail in the aforesaid patent but will be briefly described herein for purposes of clarity. The filament array extends axially of said elongated outer envelope or bulb and is mounted between a pair of upstanding rigid lead-in and support conductors 28 and 30 secured respectively to the inner ends of locating pins 22 and 24. From the upper ends of lead-in and support conductors 28 and 30 is mounted an upper bridge member of quartz or Vycor by means of a pair of resilient support wires 34. A lower transverse bridge member also of quartz or Vycor is suspended from the lead-in support conductors 28 and 30 by a pair of resilient support wires 38. The filament array 40, which may be monoplanar (a single plane of plural filaments) or biplanar (two substantially parallel planes of a plurality of filaments) are mounted between the auxiliary upper support wires 42 and the auxiliary bottom support wires 44 in the manner described in detail in US. Pat. No. 2,721 ,29l and are electrically connected to the lead-in and support conductors 28 and 30 through a pair of lead in and ballast coils 46. A centering member 48 is connected at one end to the dummy locating pin 25 and at its other end to the lower transverse bridge member 36 through a bottom guide link 50.

When the projection lamp is designed for use in a projection system that does not include a separate external reflector, an internal proximity reflector may be employed as illustrated at 49. The internal proximity reflector 49 may be mounted from the upper or lower bridge member by a reflector support strut 51.

The prior art incandescent projection lamps of this type included a fuse illustrated in phantom at 52, located as for example. within the confines of the base 12 and welded at one end to hot locating pin 23 and at the other end to dummy locating pin 22. An illustration of this prior art arrangement for a fuse may be seen in US. Pat. No. 2,859,381 to Gray, et al.

The prior art projection lamps also, because of the requirement for maintaining the alignment of the filament array, included a longitudinal support member in addition to the lateral supports 28 and 30 to provide essentially a three-point suspension for the filament array and thus maintain that array in a predetermined position with respect to the mounting and locating pins and hence the projection system in which it is intended for use.

In accordance with the present invention the separate support member and separate fuse member have been eliminated and a composite element substituted therefor which includes a three-part fuse wire and support member generally designated 54 which includes a pair of sturdy relatively heavy end portions 56 and 58 and an intermediate fuse wire member 60. The combination fuse wire and support member 54 is secured at its end 58 to the electrically hot support or locating pin 23 and extends generally away from the base and at an angle with respect to the axis of the bulb and at its other end 56 is welded to the one of the upstanding lead-in and support conductors 28 or 30 which is connected to the dummy locating pin, as for example the pin 23. As illustrated in FIGS. 1 and 2 in the specific example the end 56 of the fuse wire and support member is connected approximately one-third of the way up the leadin and support conductor 28 as for example by welding. A glass sleeve 62 surrounds the fuse portion 60 and overlies portions of ends 56 and 58 as a safety measure in order to prevent portions of the fuse wire, as it fails due to a short circuit in the filament, from impinging on and breaking through the outer envelope 14. The filament is of course connected in the circuit through the socket by means of pins 23 and 24 to thereby place the fuse element 60 in the circuit with the filament array.

As will be apparent from the foregoing the fuse wire and support member combination of this invention eliminates the necessity for a separate support member and a separate fuse member and reduces the number of welds required in the manufacture of the lamp by two without the loss of function or reliability of the projection lamp.

What is claimed is:

1. In a fused projection lamp having a base portion, a bulb portion sealed thereto, a plurality of support pins extending through said base portion and an elaborate filament array and support bridge therefor mounted within said bulb portion between a pair of upright leadin conductor support members mounted on a pair of said support pins laterally disposed one from the other, the improvement comprising:

a combination fuse wire and support member connected at one end to a third support pin and extending upwardly away from said base portion at an angle with respect to the axis of said bulb portion and connected at its other end to one of said upright lead-in conductor support members whereby electrical safety and longitudinal support are provided by a single element.

2. An improved projection lamp according to claim 1 wherein said combination fuse wire and support member comprises:

a first relatively heavy wire portion secured to said upright lead-in conductor support member and a second relatively heavy wire portion secured to said third support pin and an intermediate fuse wire portion connecting said first and second relatively heavy wire portions.

3. The projection lamp according to claim 2 wherein a glass sleeve is positioned about said intermediate fuse wire.

4. A fused projection lamp comprising: a base portion, a bulb portion sealed thereto and a plurality of support pins extending through said base portion into said bulb portion;

a pair of upright lead-in conductor support members mounted on a pair of said support pins laterally disposed one from the other;

a filament array and support bridge therefor mounted between said pair of upright lead-in conductor support members; and

a combination fuse wire and support member connected at one end to a third support pin and extending away from said base portion at an angle with respect to the vertical axis of said bulb portion and connected at its other end approximately one third of the distance up the length of one of said upright lead-in conductor support members whereby electrical safety and longitudinal support are provided by a single element.

5. An improved projection lamp according to claim 4 wherein said combination fuse wire and support member comprises a first relatively heavy wire portion secured to said upright lead-in conductor support member and a second relatively heavy wire portion secured to said third support pin and an intermediate fuse wire portion connecting said first and second relatively heavy wire portions.

6. The projection lamp according to claim 5 wherein a glass sleeve is positioned about said intermediate fuse wire.

7. A fused projection lamp comprising:

a base, an elongated bulb sealed to said base, and a plurality of rigid radially disposed locating pins extending through said base and into said bulb;

a pair of rigid lead-in conductor and support members each mounted on and rigidly affixed to a different one of said locating pins to affix said lead-in conductors in an axial orientation within said bulb and a filament array and support means therefor mounted between said rigid lead-in conductors to form a rigid composite lead-in conductor and filament mount structure;

one of. said locating pins to which one of said lead-in conductors is affixed being adapted to be connected to one terminal of an energizing potential source, and the other of said locating pins to which said other lead-in conductor is affixed constituting a dummy pin to which no terminal of an energizing potential source is adapted to be connected, and a third of said locating pins spaced from said support pins to which said rigid lead-in conductors are affixed, and said third support pin adapted to be connected to the other terminal of an energizing potential source;

rigid fuse and support assembly comprising two rigid elongated and relatively heavy electrically conducting members connected to each other in spaced relationship at one end thereof by a rigid elongated fuse member to form an elongated assembly, and an elongated electrically insulating member overfitting said fuse member and a portion of said elongated relatively heavy members;

said fuse and support assembly rigidly affixed proximate one of its ends to said third support pins, and said fuse and support assembly extending within said bulb generally away from said base and at an angle with respect to the axis of said bulb and rigidly affixed proximate its other end to said other lead-in conductor to complete electrical continuity between said lead-in conductors and said support pins which are adapted to be connected to the terminals of an energizing potential source as well as rigidly affix the positioning of said composite leadin conductor and filament mount structure;

whereby said composite lead-in conductor and fila-v ment mount structure is firmly secured within said bulb. 

1. In a fused projection lamp having a base portion, a bulb portion sealed thereto, a plurality of support pins extending through said base portion and an elaborate filament array and support bridge therefor mounted within said bulb portion between a pair of upright lead-in conductor support members mounted on a pair of said support pins laterally disposed one from the other, the improvement comprising: a combination fuse wire and support member connected at one end to a third support pin and extending upwardly away from said base portion at an angle with respect to the axis of said bulb portion and connected at its other end to one of said upright lead-in conductor support members whereby electrical safety and longitudinal support are provided by a single element.
 2. An improved projection lamp according to claim 1 wherein said combination fuse wire and support member comprises: a first relatively heavy wire portion secured to said upright lead-in conductor support member and a second relatively heavy wire portion secured to said third support pin and an intermediate fuse wire portion connecting said first and second relatively heavy wire portions.
 3. The projection lamp according to claim 2 wherein a glass sleeve is positioned about said intermediate fuse wire.
 4. A fused projection lamp comprising: a base portion, a bulb portion sealed thereto and a plurality of support pins extending through said base portion into said bulb portion; a pair of upright lead-in conductor support members mounted on a pair of said support pins laterally disposed one from the other; a filament array and support bridge therefor mounted between said pair of upright lead-in conductor support members; and a combination fuse wire and support member connected at one end to a third support pin and extending away from said base portion at an angle with respect to the vertical axis of said bulb portion and connected at its other end approximately one third of the distance up the length of one of said upright lead-in conductor support members whereby electrical safety and longitudinal support are provided by a single element.
 5. An improved projection lamp according to claim 4 wherein said combination fuse wire and support member comprises a first relatively heavy wire portion secured to said upright lead-in conductor support member and a second relatively heavy wire portion secured to said third support pin and an intermediate fuse wire portion connecting said first and second relatively heavy wire portions.
 6. The projection lamp according to claim 5 wherein a glass sleeve is positioned about said intermediate fuse wire.
 7. A fused projection lamp comprising: a base, an elongated bulb sealed to said base, and a plurality of rigid radially disposed locating pins extending through said base and into said bulb; a pair of rigid lead-in conductor and support members each mounted on and rigidly affixed to a different one of said locating pins to affix said lead-in conductors in an axial orientation within said bulb and a filament array and support means therefor mounted between said rigid lead-in conductors to form a rigid composite lead-in conductor and filament mount structure; one of said locating pins to which one of said lead-in conductors is affixed being adapted to be connected to one terminal of an energizing potential source, and the other of said locating pins to which said other lead-in conductor is affixed constituting a dummy pin to which no terminal of an energizing potential source is adapted to be connected, and a third of said locating pins spaced from said support pins to which said rigid lead-in conductors are affixed, and said third support pin adapted to be connected to the other terminal of an energizing potential source; a rigid fuse and support assembly comprising two rigid elongated and relatively heavy electrically conducting members connected to each other in spaced relationship at one end thereof by a rigid elongated fuse member to form an elongated assembly, and an elongated electrically insulating member overfitting said fuse member and a portion of said elongated relatively heavy members; said fuse and support assembly rigidly affixed proximate one of its ends to said third support pins, and said fuse and support assembly extending within said bulb generally away from said base and at an angle with respect to the axis of said bulb and rigidly affixed proximate its other end to said other lead-in conductor to complete electrical continuity between said lead-in conductors and said support pins which are adapted to be connected to the terminals of an energizing potential source as well as rigidly affix the positioning of said composite lead-in conductor and filament mount structure; whereby said composite lead-in conductor and filament mount structure is firmly secured within said bulb. 